Case Studies
Hurricane Ida: Flooded Basements Reveal Hidden Inequities
Lack of affordable housing in New York State amplifies health risks. Heavy rain can force low- and moderate-income residents out of their homes and threaten their lives.
When Hurricane Ida struck New York City, residents of basement apartments and other flood-prone areas had little to no warning about floodwaters that entered their apartments. One Black woman’s experience during the hurricane illustrates how climate change brings new risks and amplifies longstanding issues for those who lack safe, affordable housing.
In 2021, Nia was a first-year attorney who had moved to New York City from Buffalo about a decade earlier.1 She was living in a three-level townhouse in Brooklyn with her sister and another housemate. Nia’s bedroom was in the basement, which also had a bathroom and a window into a window well that connected to the backyard. On the night of September 1, 2021, when Hurricane Ida reached New York City, Nia was at home and receiving city weather advisories on her phone. She knew that forecasts predicted high wind and rain. Having been in the city during Superstorm Sandy, Nia knew that her home was not in an area vulnerable to flooding from any bodies of water.
Highlights
- Extreme rainfall events such as Hurricane Ida threaten those who occupy less-safe housing, increasing risks to New Yorkers’ health and well-being.
- Raising risk awareness and offering coping resources will be critical to helping residents adapt.
At around 9 p.m., Nia heard the rain intensify. Around 10 p.m., water suddenly came up through the bathroom drain, and a gush of water pushed the window air conditioning vent into the room. The water quickly became ankle deep. Nia grabbed her puppy and ran for the stairs to the first floor. Within minutes, water rose to the ceiling in the basement (see photo). The water continued to rise for the next half hour, eventually reaching the first floor.
Unable to exit the building because all exits were submerged, the three housemates went to the upper floor and called emergency services. Emergency personnel eventually arrived and communicated with them through a window. The housemates agreed to shelter in place until the morning, when the water receded enough to allow them to leave the building. Many other residents experienced flooding that night in New York City (Figure 1), and 11 people died in basement apartments.2
Flooding Vulnerabilities
As Hurricane Ida demonstrated, climate events tend to amplify pre-existing vulnerabilities.3 The fatal flooding in New York City basement apartments, which are often most affordable, is one example of this issue. Unfortunately, the City of New York lacks data identifying basement apartments across the five boroughs,4 which makes it difficult to monitor those apartments for code compliance or assess where New Yorkers may be at greater risks from pluvial flooding (flooding that occurs when the ground is saturated or impervious and cannot absorb or drain excess water).5 Moreover, even if apartments were fully documented, flooding vulnerabilities would remain. New York City has limited availability of safe and affordable housing alternatives. In New York State’s urban areas, high housing demands and a high percentage of impervious surfaces coincide. These factors combine to amplify health risk. The state recently mandated identification of prior flooding in lease disclosures,6 and has provided information resources to existing residents to increase their awareness of flood risks and options for safe shelter.7
Current Climate Impacts
In extreme rain or cloudburst events, large amounts of precipitation fall very quickly and overwhelm existing drainage systems, flooding streets, subways, and basements. The extent of cloudburst flooding can exceed floodplains mapped by the Federal Emergency Management Agency.5 Unless such flooding has been recently experienced, individuals may not be aware of their personal risks (as demonstrated in a modeling project in Syracuse).9 While New York City recognizes this problem and is working through various cloudburst strategies, the increase in cloudburst events over the last decade elevates risks for a large number of households.10
Eleven people died in New York City as a result of flooded basements during Hurricane Ida.2 The immediate impact of flooding of numerous homes and businesses extended to long-term recovery for cleanup, including rebuilding and mold removal. Even as mold remediation companies worked overtime to respond to calls, they could not meet the demand.11 Moreover, many residents could not afford to hire such companies, or even afford to replace flooded furniture, leading to long-term mold exposure and worsening respiratory conditions. Without strategies for risk avoidance, and with limited resources for recovery, many New Yorkers remain exposed to flood risk.
Amplifiers
High housing costs drive people to seek lower-cost options, such as basement apartments, which can be vulnerable to flooding. Former New York City Mayor Bill de DeBlasio’s team estimated that there are more than 50,000 illegal basement apartments in the city, housing at least 100,000 people.12,13 Since basement apartments are not always legal, landlords have less of an incentive to make tenants aware of risks. As Black women, the two sisters in this case study represent a demographic that is overly burdened with climate risks due to historical injustices, present-day job-related risks (e.g., commuting distance), and other factors.14 Undocumented immigrants, many of whom often share basement apartments as their first housing in New York City, lack recourse when floods occur.15 Most of those who died during Hurricane Ida’s basement floods in New York City were Asian immigrants, a group for whom language access and risk messaging pose a significant challenge.16
Adaptation in Action
New York City is pursuing initiatives to better understand cloudburst events, since these events differ from typical rain events and coastal storms. The New Normal report identifies ongoing actions to alleviate the impacts of extreme weather.17 Rainproof NYC identifies types of areas that could adapt to these events.18 The New York City Housing Authority (NYCHA) is implementing cloudburst strategies at South Jamaica as a way to pilot multi-benefit solutions for community well-being and stormwater management.19 The cloudburst pilot project includes three adjacent public spaces that will help to manage stormwater while meeting community needs: sunken seating spaces and native plant area that includes pervious pavers to soak up daily rain events; sunken basketball courts with underground retention tanks to hold high volumes of stormwater and integrated seating; and a new public path that connects the new spaces to an existing community garden.19 NYCHA also recently partnered with the Urban Land Institute to create a toolkit of adaptation options for future NYCHA improvements.20
Community-based organizations are also working on this issue. The Citizens Housing and Planning Council reported a considerable drop out of the East New York Basement Apartment Conversion Pilot Program due to unwieldy requirements and extensive costs. The Cypress Hills Local Development Corporation also hosts a basement legalization pilot.21 Legalizing basement apartments that meet health and safety standards, including flood protection measures, would be beneficial.
New York City is in the process of developing a flood vulnerability index to characterize risk. In parallel, the New York City Panel on Climate Change is exploring a climate and displacement index to address inequitable impacts of displacement risks. These two resources will offer further insights on how to visualize and address risks.22
During pluvial flooding that occurred in the summer of 2023 in New York City, Notify NYC began push notifications via their warning system app, encouraging those in basements to seek higher ground.23,24 Also, the Mayor’s Office of Climate and Environmental Justice launched the FloodHelpNY campaign.25 FloodHelpNY works with New Yorkers to improve risk awareness, as well as provide information on insurance, retrofit options, and potential funding sources.
While these adaptations offer resources and helpful information, progress will take time and require policy changes and renovations. During that time, many New Yorkers will remain vulnerable to flood inundation and mold and toxin exposure.
Moving Forward
Since cloudburst events are difficult to predict, households lack basic knowledge of their risk levels and options. Raising risk awareness and offering coping resources will be critical to helping residents adapt. A community outreach campaign could help by recognizing past challenges and preparing for future events—for example, by identifying shelters and aligning with the Ready NYC warning system. Since many New Yorkers are renters who have little control over flood hazard mitigation measures, programs that offer information on how to prepare and respond to floods could improve outcomes. Because New York City evacuation shelters activate only when a flooding event occurs, it is difficult to develop consistent community response plans. Improvements in warning systems, emergency response, and household ability to safely shelter at home—along with access to safe housing—are key to health risk reduction.10,26–28
While Nia was not physically harmed when her basement residence flooded, she ended up leaving the city and returning to Buffalo to be closer to extended family—a type of climate-driven migration that is not well documented. Nia understood flood risks, but did not understand how her current home was exposed to those risks. Risk awareness might have made a difference in Nia’s decisions and outcome.
For some New York City residents, there are few alternatives for affordable housing. Improved risk awareness without options to relocate may not alter risky behaviors. While the flooding in Nia’s apartment drove her to relocate, some residents lack such choices and remain in harm’s way.
For More Information
- New York City Department of Environmental Protection: Cloudburst Management
- Basement Apartments Safe for Everyone (BASE) Campaign
References
1. Jael Bronner, N. (2022, October 10). [Personal communication].
2. Zaveri, M., Haag, M., Playford, A., & Schweber, N. (2021, September 2). N.Y.C. storm deaths highlight shadow world of basement apartments. The New York Times. https://www.nytimes.com/2021/09/02/nyregion/nyc-basement-apartments-flooding.html
3. Thomas, K., Hardy, R. D., Lazrus, H., Mendez, M., Orlove, B., Rivera‐Collazo, I., Roberts, J. T., Rockman, M., Warner, B. P., & Winthrop, R. (2019). Explaining differential vulnerability to climate change: A social science review. WIREs Climate Change, 10(2), e565. https://doi.org/10.1002/wcc.565
4. Zaveri, M. (2021, September 14). 11 deaths put focus on N.Y.C.’s failure to make basement apartments safe. The New York Times. https://www.nytimes.com/2021/09/14/nyregion/legalize-basement-apartments-nyc.html
5. Mills, C. K., Nair, A., & di Giovanni, J. (2023, November 17). Flood-prone basement housing in New York City and the impact on low- and moderate-income renters. Liberty Street Economics. https://libertystreeteconomics.newyorkfed.org/2023/11/flood-prone-basement-housing-in-new-york-city-and-the-impact-on-low-and-moderate-income-renters/
6. New York Senate Bill S5472A, 2021-2022 legislative session. https://www.nysenate.gov/legislation/bills/2021/S5472
7. New York City Department of Environmental Protection. (n.d.). Rainfall Ready NYC: Plan for intense storms. Retrieved January 3, 2024, from https://www.nyc.gov/site/dep/whats-new/plan-for-intense-storms.page
8. Capurso, W. D., Simonson, A., Noll, M. L., Busciolano, R., & Finkelstein, J. (2023). High-Water Marks in the five boroughs of New York City from flash flooding caused by the remnants of Hurricane Ida, September 1, 2021 [dataset]. U.S. Geological Survey. https://doi.org/10.5066/P9OMBJPQ
9. Pereira Marques, Y. (2021). Assessment of pluvial flooding in Syracuse, NY, using high-resolution topographic data. https://surface.syr.edu/thesis/576
10. New York City Emergency Management Department. (n.d.). Flooding. NYC Hazard Mitigation Plan. Retrieved January 8, 2024, from https://nychazardmitigation.com/documentation/hazard-profiles/flooding/#how-to-manage-the-risk
11. Denton, J. (2021, September 10). If you’re worried about mold after the flooding, get in line. Curbed. https://www.curbed.com/2021/09/mold-remediation-hurricane-ida.html
12. New York City Office of the Mayor. (2021, September 3). Transcript: Mayor de Blasio holds media availability. Retrieved November 8, 2022, from http://www1.nyc.gov/office-of-the-mayor/news/599-21/transcript-mayor-de-blasio-holds-media-availability
13. Hogan, G. (2022, July 12). NYC basement apartments are still unregulated, despite Hurricane Ida deaths last fall. NPR. https://www.npr.org/2022/07/12/1111131985/nyc-basement-apartments-are-still-unregulated-despite-hurricane-ida-deaths-last-
14. Hornbach, C., Levers, A., & Yeung, L. (2022). Bringing basement apartments into the light. New York City Comptroller. https://comptroller.nyc.gov/reports/bringing-basement-apartments-into-the-light/
15. Whitford, E. (2023, March 13). In New York’s fight to legalize basement apartments, what about cellars? City Limits. https://citylimits.org/2023/03/13/in-new-yorks-fight-to-legalize-basement-apartments-what-about-cellars/
16. Yam, K., & Venkatraman, S. (2021, October 18). Ida’s forgotten victims: Nearly all storm’s basement deaths were Asian residents, obscured by climate injustice. NBC News. https://www.nbcnews.com/news/asian-america/ida-s-forgotten-victims-nearly-all-storm-s-basement-deaths-n1281670
17. New York City Extreme Weather Response Task Force. (2021). The new normal: Combating storm-related extreme weather in New York City. Retrieved April 12, 2022, from https://www1.nyc.gov/assets/orr/pdf/publications/WeatherReport.pdf
18. Rebuild by Design & One Architecture and Urbanism. (2022). Toward a rainproof New York City: Turning the concrete jungle into a sponge. https://www.rebuildbydesign.org/wp-content/uploads/2022/08/Rainproof-NYC-Turning-the-Concrete-Jungle-into-a-Sponge-Compressed.pdf
19. New York City Housing Authority & New York City Department of Environmental Protection. (2019). NYCHA: South Jamaica houses cloudburst master plan 2018. https://www1.nyc.gov/assets/nycha/downloads/pdf/NYCHA-South-Jamaica-Clouburst-Plan-Report-2019.pdf
20. Barnes, J., & Temko, L. (2022). New York, NY: Cloudburst infrastructure workshop for New York City Housing Authority [Technical assistance panel report]. Urban Land Institute. https://knowledge.uli.org/en/Reports/TAP/2022/ULI%20New%20York%20NYCHA%20Cloudburst%20Infrastructure%20Workshop
21. Citizens Housing Planning Council. (n.d.). Basement Apartment Conversion Pilot Program interim report. Retrieved August 24, 2023, from https://chpcny.org/publication/basement-apartment-conversion-pilot-program-interim-report/
22. New York City Mayor’s Office of Climate & Environmental Justice. (n.d.). Climate vulnerability, impact, and adaptation analysis (VIA). Retrieved January 4, 2024, from https://climate.cityofnewyork.us/initiatives/vulnerability-impacts-and-adaptation-analysis/
23. New York City Emergency Management Department. (2023). NYC Emergency Management advises New Yorkers to prepare for potential severe thunderstorms and flash floods. Retrieved August 24, 2023, from https://www.nyc.gov/site/em/about/press-releases/20230715_pr_nycem_nyers-prepare-flash-floods.page
24. Notify NYC. (n.d.). About Notify NYC. Retrieved January 4, 2024, from https://www.nyc.gov/site/em/resources/notify-nyc-app.page#:~:text=The%20Notify%20NYC%20mobile%20application,you%20are%20in%20the%20city.
25. FloodHelpNY. (n.d.). About Us. Retrieved November 21, 2023, from https://www.floodhelpny.org/en/about
26. New York City Emergency Management Department. (n.d.). Rising above: Citywide flood preparedness Day of Action & resource fair. Retrieved January 8, 2024, from https://www.nyc.gov/site/em/ready/rising-above.page
27. New York City Mayor’s Office of Climate & Environmental Justice. (n.d.). Coastal flood adaptation. Retrieved January 8, 2024, from https://climate.cityofnewyork.us/initiatives/coastal-flood-adaptation/
28. New York State Office of the Governor. (2023). Governor Hochul and the National Weather Service announce flood safety awareness week in New York State. Retrieved January 8, 2024, from https://www.governor.ny.gov/news/governor-hochul-and-national-weather-service-announce-flood-safety-awareness-week-new-york